1. Field of the Invention
The present invention relates generally to filter devices and more particularly to a new and improved bacteria filter device designed to effectively filter bacterial matter from fluids passing therethrough while rigidifying a pleated cylindrical filter element. The invention further relates to the method of assembling the filter device so that the cylindrical pleated filter element is retained in the desired form during assembly of the filter device.
2. Description of the Prior Art
In certain artificial respiratory systems, such as intermittent positive pressure breathing systems (IPPB), used in assisting asthma patients with breathing, air purifiers or bacteria filters are used to remove undesirable bacteria from the fluid sprayed into the patient's mouth. A typical IPPB system has a nebulizer nozzle designed to cooperate with a nebulizer filter in spraying the desired fluid into the patient's mouth. A typical IPPB system also includes a main line filter having a greater capacity for purifying the main line air flow. Filters which have been found desirable in obtaining high capacity filtration while being compact in size have utilized a pleated generally cylindrical filter element, but while these filter elements give the optimum in filtering capacity for a designated filter size, they have length limitations since physical strength of the element diminishes with the length and long filter elements may collapse in use reducing the efficiency and reliability of the filter device. Further, pleated filters of the aforedescribed type have previously been difficult to position and retain within the filter device with the pleats uniformly spaced in a circular array.